In commencing on this subject a writer in the Lancet recently remarked: "Diabetes is a disease full of interest, owing in great part to the lacunœ that still exist in our knowledge of its essential nature."

He is most certainly right in thus assigning imperfection and uncertainty of information as the reason for medical and scientific interest in this matter.

Mooted questions are always those about which medical contest is sharpest and medical interest is keenest, while settled facts are left to stand as landmarks of progress, or as foundations for new structures of experiment and theory.

It is emphatically true that as regards the causes underlying the symptoms classed together under the term diabetes, the "lacunœ" are abnormally large and the interstitial substance of fact is uncomfortably thin.

Numberless theories of causation have been advanced, and probably will continue to be until a satisfactory etiology is established. But whether